This is stated in the report of the Cabinet of Ministers of Ukraine posted on the governmental portal.
"The coal supplies were diversified: the imports from Russia in 2015 amounted to 628,000 tons, which is 69% less than in 2014. The imports from South Africa in 2015 increased by 139% and amounted to 897,000 tons (against 376,000 tons in 2014)," reads the document.
The natural gas supplies were diversified, "The total volume of gas imports to Ukraine in January-December 2015 decreased by 15.5% to 16.5 billion cubic meters (against 19.5 billion cubic meters over the corresponding period in 2014). In particular, the gas imports from Russia decreased by 57.3% to 6.1 billion cubic meters while the gas supplies from the EU doubled to 10.3 billion cubic meters."